Sought to motivate college students to reduce the number of miles they drove each day and thus save gasoline. The 12 experimental Ss were offered various combinations of prizes such as cash, car servicing, and a university parking sticker for reducing driving. The value of the prize received was scaled in terms of percent reduction in driving. The contrast group of 9 Ss received no inducements. The condition in which the experimental group's mileage reduction was reinforced was counterbalanced by 2 baseline conditions. Several special recording procedures were used to reduce and detect the possibility of Ss altering their odometers, the source of the driving data. Experimental Ss reduced their average daily mileage by 20% relative to the initial baseline; the contrast group did not change. During the 1-mo reinforcement condition, experimental Ss saved some 170 gallons (worth $102) of gasoline.